Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Jul. 31, 2015	Sep. 01, 2015	Apr. 30, 2015	Jul. 31, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Investments in available-for-sale securities	$ 406,360		$ 439,625	$ 403,774
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,500,000
Minimum [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Accelerated Share Repurchases, Final Price Paid Per Share	$ 32.25
Maximum [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Customer Deposits	$ 419,000
Accelerated Share Repurchases, Final Price Paid Per Share	$ 37.00
HRB Bank [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Customer Deposits	$ 477,145		$ 744,699	$ 483,477
Collateralized Mortgage Backed Securities [Member] | Other Long-term Investments [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Investments in available-for-sale securities	$ 404,221
Subsequent Event [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Stock Repurchase Program, Authorized Amount		$ 3,500,000
Subsequent Event [Member] | Tender Offer [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Stock Repurchase Program, Authorized Amount		$ 1,500,000